Any rule-of-thumb for replacing 4.5" cutoff wheels?

   #1  

newbury

Super Star Member
Joined
Jan 8, 2009
Messages
11,882
Location
From Vt, in Va, retiring to MS
Tractor
Kubota's - B7610, M4700
I've read of them shattering and I'm apprehensive of getting shards in my body even though I wear PPE.
But presently the roofing metal I'm cutting is eating about 1 Dewalt DW8062 wheel per panel width.
 
   #2  

sea2summit

Elite Member
Joined
Mar 6, 2012
Messages
3,079
Location
Left coast of, GA
Tractor
Kubota 1860->25D, MX5800, M4D
I cut roofing metal with my skilsaw, way faster, easier and I think safer. I dedicate my old blades to that task. But when I use a grinder I go until I can't cut all the way through a channel of the roofing then swap out so probably ~40% smaller when I'm done?
 
   #6  

Birdhunter1

Veteran Member
Joined
May 5, 2004
Messages
1,761
Location
Murphysboro, IL
Tractor
Mahindra 2638
If you are using it to cut look for one of those Diablo or Lenox diamond metal cutting blades. On 1/4" steel they don't cut as fast as an abrasive cutting wheel but they last 1000times longer.
 
   #8  

Deere Dude

Elite Member
Joined
Feb 10, 2011
Messages
3,913
Location
Beaver Dam Wisconsin then to Hohenwald, TN
Tractor
John Deere 3720
I've read of them shattering and I'm apprehensive of getting shards in my body even though I wear PPE.
But presently the roofing metal I'm cutting is eating about 1 Dewalt DW8062 wheel per panel width.
That sounds about right in my experience. Cutoff discs don't last long but are cheap. I recently cut about 20-30 8" I beams with a stack of these. Just need to go slow and no twisting. There are maybe better options as noted by others but I have about 50 more to go through and they work. Just keep a wrench handy.
 
   #9  

KennyG

Elite Member
Joined
Jan 13, 2011
Messages
3,830
Location
SW Michigan
Tractor
John Deere 2320
For roofing, use a circular saw with a metal cutting blade. The grinder will heat the metal too much and be more likely to cause rust issues in the future. I made all the cuts necessary for my pole barn with one metal cutting blade and it's still in good shape.
 

TractorGuy

Elite Member
Joined
Sep 15, 2013
Messages
4,611
Location
N. FL
Tractor
John Deere 4310 CUT, Ford New Holland 575E Industrial Backhoe, John Deere F725 Front Mount Mower
Never use them without wearing protective gear and clothing.

When I use abrasive cut off wheels I have a face shield, leather arm covers, leather apron, and leather gloves on.

I use the 4-1/2" discs until they wear down to the grinder head.

I have had a few come apart. If I see a nic in the edge I throw it away. I had a 7" disc explode on my chop saw and shatter the guard. One piece actually hit my face shield. 99% of the time they wear evenly until they are worn out.
 

pmsmechanic

Elite Member
Joined
Dec 6, 2013
Messages
3,663
Location
Southern Alberta, Canada
Tractor
4410 and F-935 John Deere, MF 245
I used to cut roofing metal with a skill saw with a backwards blade. It worked ok but was quite noisy and left a poor finish. My buddy says to me why aren't you using a good pair of scissor type tin snips? Why indeed? I'll never go back to grinding or a skill saw. Tin snips are quick and easy to use and.... quiet.
 

Industrial Toys

Super Star Member
Joined
Feb 25, 2008
Messages
17,400
Location
Ontario Canada
Tractor
Kubota R510 Wheel Loader + Cab and backhoe, JD 6200 Open Station, Cushman 6150, 4x4, ten foot 56 hp Kubota diesel hydraulic wing mower, Steiner 430 Diesel Max, Kawasaki Diesel Mule, JD 4x2 Electric Gator
Most (if not all) violent failures I have experienced were precipitated by catching the wheel on something and taking a chunk out of it. Then you better look out!
 

oosik

Super Star Member
Joined
Aug 22, 2012
Messages
17,015
Location
AMBER, WA
Tractor
2009 Kubota M6040
Long ago I worked at a facility where the Ingersol-Rand tools used 6" cutting wheels. Infrequently - one would fragment. Never knew why. Everybody blamed it on improper use of the tool. Leather gloves, long sleeved shirts and heavy duty plexiglass face shields were the word of the day.

Most wore leather welding jackets when using these cutters.
 

triptester

Silver Member
Joined
Jun 19, 2011
Messages
217
Location
central,wi.
Tractor
TYM 350
When using cutoff wheels I found that they don't work well if you try to use them like a saw, where you cut all the way thru as you move forward. When cuts of more than a few inches need to be made I place a metal straight edge where a line is scored. Then with light pressure and moving back and forth grind thru. With this method making a 4 foot cut thru 3/16" diamond plate takes one 4 1/2" cutoff wheel.
 

PILOON

Super Star Member
Joined
Aug 26, 2004
Messages
10,862
Location
North of Mtl,Que,Can (Ste Adele)
Tractor
MT180D
get a blade for steel for your circ saw.
Yep!
I found such a blade (rare) that looks like a standard saw blade but has no teeth, just a lot of slits.
The call it a 'friction blade'.
I've made a whole lots of roofing cuts and that blade is still good to go.
Downside is it creates a lot of 'steel wool' like remnants as well as leaving a scorched (1/8") like trace on the cut metal.
OK for thin (roof like) metal but not for thicker stock.
 

DL Meisen

Elite Member
Joined
Apr 6, 2018
Messages
3,799
Location
A Little Bit West Of Yosemite NP
Tractor
MF GC1715
Use skill saw with carbide tipped blade and a lot of safety gear... Not a angle grinder...


Angle grinder cutoff.jpg
 

3Ts

Veteran Member
Joined
May 27, 2017
Messages
2,258
Location
East Texas
Tractor
Case, Kubota, John Deere
If you're cutting the steel roofing for a metal building, try using an air powered nibbler. I've found it works better than any saw and is fast.
 

3Ts

Veteran Member
Joined
May 27, 2017
Messages
2,258
Location
East Texas
Tractor
Case, Kubota, John Deere
i7win7 - what is your tractor pulling in your avatar? Is that a dirt pan? Do you have a bigger picture?
 

34Willys

Bronze Member
Joined
Apr 6, 2011
Messages
92
Location
Upper Lake, CA/Glide,OR
Tractor
'92 Kioti LK3054 '18 Kioti CK2610HST
Nibbler....... then draw file as, or, if needed.
Have done many aircraft skin repairs and metal roofing trimming with those tools.
A & P Patrick
 
   #22  

amhicks21

Silver Member
Joined
Aug 28, 2015
Messages
169
Location
saginaw, michigan
Tractor
l6060 kubota
Ive used many hundreds of cutoffs over the years with only very few incidents. When possible I run em right down to nothing. The problem with cutting roofing is the metal will start to vibrate and will destroy the disc in seconds if you let the blade get in too deep or bind. The other problem with thin metal is it gets hot quick and expands and pinches the side of the disk. You can mostly avoid this by keeping the blade very shallow and do whatever possible to keep the blade from pinching. Maybe try rotating the guard into a position that acts as a depth gauge and only let the blade come 1/4" through the bottom and, as everyone knows but it always bears repeating let the disk do the work and only guide it along without pushing.
 
   #23  

California

Super Star Member
Joined
Jan 22, 2004
Messages
12,499
Location
Sonoma County
Tractor
Yanmar YM240, and now just one YM186D
FWIW, Project Farm did a comparison of cutoff blades. DeWalt took 2.5 times longer than the majority of them.

See the 7:29 point in this video.


There are other conclusions a few seconds either side of that point.

I ordered a pack of Makita blades yesterday after studying the video. He showed that these aren't consumed as fast, while taking the same time to cut as most others.

Back when I was a carpenter it was common practice to mount a Skilsaw blade backward to cut sheet metal.
 
   #24  

ArlyA

Elite Member
Joined
Mar 18, 2016
Messages
4,902
Location
Houghton MI (the Lake Superior snow belt) USA
Tractor
Polaris Boss 6x6 with pods (tracks) Center actuating lawn mower by Husky
I love my 4.5 Porter cable grinder, but I'd not use it for cutting tin. And like others have pointed out, cheap wheels are just that. Cheap! :sick:
 
   #25  

PILOON

Super Star Member
Joined
Aug 26, 2004
Messages
10,862
Location
North of Mtl,Que,Can (Ste Adele)
Tractor
MT180D
Back when I was a carpenter it was common practice to mount a Skilsaw blade backward to cut sheet metal.
Sort of like what I posted earlier.
A friction blade is very similar to a regular saw blade but without teeth, just all the slits.
Rare to find but sure does a great job.
 
   #26  

rangerfredbob

Platinum Member
Joined
Jan 2, 2019
Messages
897
Location
Dayton, Oregon
Tractor
Kubota L260
I bought some new Milwaukee tin snips for doing the siding on my shop, like a hot knife through butter... I used those over an electric double cut shear I had borrowed and an air nibbler... If the metal is just currogated and not the one rib per 9" like I have they would be a pain though...
 
   #27  

aviator411

New member
Joined
Nov 2, 2006
Messages
1
Manufacturers of steel roofing, paneling, siding do not approve of cutting their panels with any kind of saw blade or abrasive disc due to heat produced degrading finish and accelerating rust process. Power or manual shears only if you possibly can. Not always an easy option.
 
   #28  

nknelsen

Member
Joined
Mar 13, 2017
Messages
47
Location
barrie, Ontario
Tractor
CX2510 with FEL
I've read of them shattering and I'm apprehensive of getting shards in my body even though I wear PPE.
But presently the roofing metal I'm cutting is eating about 1 Dewalt DW8062 wheel per panel width.
I find that the cutting wheels generate too much heat when cutting and that will affect the paint and possibly cause corrosion later on. When I did my metal roof it was suggested that I not use a grinder for that reason.

I used a Dewalt Sawzall with a 6"metal blade that worked very well for cutting. On my average size house I think I cut it all with 2 or 3 blades. Much safer too in my opinion.
 
   #29  

Bullwinkle123

Platinum Member
Joined
Mar 30, 2019
Messages
643
Location
Southern VT
Tractor
Kubota MX5400HST, Z724XKW-3-54
Don't buy harbor freight cutting wheels...stick with diablo or dewalt.

I happen to like my HF cutting wheels. They're cost effective and have a thin kerf that I prefer when cutting.

That said, I suppose the thinner disks are even more likely to shatter, though I haven't had any shatter. Always something to worry about with any brand.
 
   #31  

macklong

New member
Joined
Jul 25, 2005
Messages
17
Location
Idaho
Tractor
JCB MIDI CX4, 1949 Farmall supper A, Polaris Ranger 900XP
Not sure if any of you have heard of this but i use a 4" twin cut saw. it's resembles a 4" angle grinder but it is not the same and can not be used as a twin cut saw. one blade turns one direction the other turns the other, it uses carbide tip blades and they last a very long time. I first was a bit skeptical but decided to make the plunge and now i am so glade I did. After getting it I thought i would put this to a test on stainless steel about an 1/8" thick, wow what a job it did went through it like butter. I am still using the same blades and it has been a good ten years now. ( not in business just DIY stuff) It makes very small chips so i wear gloves and face shield and it does make a lot of noise and some sparking so be careful on where you do your cutting. It cuts metal roofing fast and almost no burs left on the metal. I have learned through trial an era that if you clamp a board to the metal roofing that it does not flex and makes it easier to make a clean straight cut.
 
   #32  

BeezFun

Veteran Member
Joined
Jul 1, 2009
Messages
2,307
Location
IL
Tractor
Kubota B2710
I rented this shear when I installed pro rib on my buildings, best thing I've ever seen for cutting across roofing with raised contours. Only problem is it's specific to the brand roofing you're using.
 
   #33  

ArlyA

Elite Member
Joined
Mar 18, 2016
Messages
4,902
Location
Houghton MI (the Lake Superior snow belt) USA
Tractor
Polaris Boss 6x6 with pods (tracks) Center actuating lawn mower by Husky
Great find! But what would you do to cut just one pannel off?? Or those shears aren't available to rent where you reside??
 
   #35  

v908

New member
Joined
May 27, 2012
Messages
21
Location
Agua Dulce, CA
Tractor
Yanmar F18D
This guys test of blades and grinding wheels rocks! (y)

Yeah, it's worthwhile to go back through his videos to see all the stuff he tests. Generally very thorough and informative.
 
   #36  
Joined
Jan 1, 2010
Messages
25
Location
Crooked River, Sask
Tractor
MF 1533 Hydrostatic c/w FEL - Quick Attach Bucket & Forks
I am a carpenter who has installed a lot of metal to buildings. I never use Zip Cut blades unless absolutely necessary, they cause sparks that will ignite fires, they wear out, they burn the paint on the metal and they can explode. I know a guy who was using a ZipCut that exploded. Schapnel went thru his glove and cut a vein in his wrist. Not a pretty sight and major 1/2 hr rush to the hospital.
I use a 7 1/4" -metal cutting- carbide blade in a circular saw, or tin nibbler connected to an air hose. I made up a track for the saw to run in for straight cuts, just measure, clamp down the track and cut. And maybe a little filing of the cut.
Also if I need to cut numerous sheets, to the same size. I can cut 4 or 5 sheets at the same time. And carbide blade lasts quite awhile. I can do two to three major projects on one blade. Cheaper that buying abrasive blades, over the long run
You still need PPE, hearing protection (its noisy), gloves with high gauntlet (the cuttings are hot) and preferably a face shield
 
   #37  

zozomike

New member
Joined
May 3, 2014
Messages
11
Location
Capitan
Tractor
Earth Force 2 and 1954 Ford NAA
Having done a good bit of metal roofing, the best ( and I think safest) cuts were with a steel circular saw blade, mounted backwards, will cut all day long. Not talking a specialty metal cutting blade, just a cheap steel 7 inch. MOUNTED BACKWARDS. Do not ever try that mounted forwards.
 
   #39  

Industrial Toys

Super Star Member
Joined
Feb 25, 2008
Messages
17,400
Location
Ontario Canada
Tractor
Kubota R510 Wheel Loader + Cab and backhoe, JD 6200 Open Station, Cushman 6150, 4x4, ten foot 56 hp Kubota diesel hydraulic wing mower, Steiner 430 Diesel Max, Kawasaki Diesel Mule, JD 4x2 Electric Gator
You don't know if companies like dewalt have different sources for different markets. And whether they outsource their supply. Say put out a tender for a million cutoff wheels. Next batch, might be from somewhere else entirely
 
   #40  

California

Super Star Member
Joined
Jan 22, 2004
Messages
12,499
Location
Sonoma County
Tractor
Yanmar YM240, and now just one YM186D
You don't know if companies like dewalt have different sources for different markets. And whether they outsource their supply. Say put out a tender for a million cutoff wheels. Next batch, might be from somewhere else entirely
Very likely. Project Farm in the video linked above, measured the DeWalt blade at 67% thicker than advertised. No wonder it was the slowest.
 
  
  • Thread Starter
#41  
OP
newbury

newbury

Super Star Member
Joined
Jan 8, 2009
Messages
11,882
Location
From Vt, in Va, retiring to MS
Tractor
Kubota's - B7610, M4700
Very likely. Project Farm in the video linked above, measured the DeWalt blade at 67% thicker than advertised. No wonder it was the slowest.
And at 7:34 in the video he listed DeWalt as the lowest cost to cut steel. The others cut faster but cost more.
I'm retired, time is not always money.
 
   #42  

California

Super Star Member
Joined
Jan 22, 2004
Messages
12,499
Location
Sonoma County
Tractor
Yanmar YM240, and now just one YM186D
And at 7:34 in the video he listed DeWalt as the lowest cost to cut steel. The others cut faster but cost more.
I saw that. Normally I will buy cheapest available that can do the job, I'm not in a hurry. I use a lot of HF stuff.

But cutting with an angle grinder seems to me a special situation where I want to reduce the time I'm exposed to risk, considering the potential of a disc grenading as some have described. A slow-cutting disc would encourage feeding it harder to cut faster, increasing risk. The DeWalt took about double the time compared to most of the others.

Considering everything in his video, I bought Makita cutoff discs. He didn't summarize in a chart, but as he tested discs he showed how much the diameter of each was reduced during the test cut. So there will be less time wasted to re-mounting fresh discs during a project. Makita was among his faster discs and lost about the least diameter. As a good name brand it might be less likely to come apart compared to HF or all the no-name brands on Amazon. So his video persuaded me that paying slightly more for Makita optimized the criteria I was looking for.
 
   #44  

DieselBound

Elite Member
Joined
Aug 9, 2016
Messages
3,275
Location
Arlington, WA
Tractor
Kubota B7800; Kioti NX5510HC
What all you guys got agin orderin steel cut to right length?

Don't you got Amishman wid roller near you?
A couple years back I cut up a bunch of panels (with circular saw with reversed blade- I tried all sort of other implements, and none were able to effectively manage the ribs). I was using the material for skirting on a manufactured home; about 30" in height. Couldn't order in such a short size so I ordered about twice required length and cut approximately in half. For sure, look to order in lengths such that you don't have to cut!
 
   #45  

ArlyA

Elite Member
Joined
Mar 18, 2016
Messages
4,902
Location
Houghton MI (the Lake Superior snow belt) USA
Tractor
Polaris Boss 6x6 with pods (tracks) Center actuating lawn mower by Husky
We get roofing up here from MS or metal sales and as as I know, they'll cut it to any length you'd like. I've ordered 2 pieces three feet in length in the past....
 
   #46  

truckdiagnostics

Platinum Member
Joined
Nov 29, 2013
Messages
922
Location
Central WI
Tractor
7753 bobcat
I use these. I have found it is a wash on price they last longer, lots longer. Saves changing discs. I believe it solves some of the safety issues others have mentioned
 
   #47  

DieselBound

Elite Member
Joined
Aug 9, 2016
Messages
3,275
Location
Arlington, WA
Tractor
Kubota B7800; Kioti NX5510HC
We get roofing up here from MS or metal sales and as as I know, they'll cut it to any length you'd like. I've ordered 2 pieces three feet in length in the past....
Great, when I need short pieces again I'll order from MI! :LOL:
 
   #49  

jjeff

Platinum Member
Joined
Jan 2, 2011
Messages
881
Location
MI
Tractor
kubota l2850, kubota l4150
I use these they are better than hf are pretty durable and cost less. I can't stand cutting with thicker wheels.
S SATC Cutting Wheel 50 PCS Cut Off Wheel 4.5"x.040"x7/8" Cutting Disc Ultra Thin Metal & Stainless Steel
4.5inch 50PCS, there on Amazon.
As others have said cut straight and don't put a lot of pressure on it or use a skill saw with metal blade.
 
   #50  

Pete O

Silver Member
Joined
Apr 8, 2016
Messages
122
Location
Victoria, Australia
Tractor
Ford 4100
I used to build sheds for a living- big sheds. Tried many methods for trimming roof and wall sheets. A normal wood saw mounted backward in a circular saw was the best power-tool method. Better still is a pair of quality tin snips. Stand on one side of the cut and pull up on the other side with your free hand and you can cut all the way across a sheet, following a pencil line, in a few seconds.
 
 
Top